qcacld-3.0: Remove PowerUsageControl from struct hdd_config

As part of change Iac183da52495aca07c6270edeb9f383ab49c1ff5
("qcacld-3.0: Add CFG items of power") support for the INI item
"gPowerUsage" was moved from HDD to MLME. However that change left
behind the PowerUsageControl field in struct hdd_config. This is now
obsolete, so remove it.

Change-Id: If5eb74b91f79288a2431b0e806ad89cd3d41b503
CRs-Fixed: 2368702

core/hdd/inc/wlan_hdd_cfg.h

@@ -2654,7 +2654,6 @@ struct hdd_config {
 
 	/* Config parameters */
 	bool enable_connected_scan;
-	char PowerUsageControl[4];
 	enum hdd_dot11_mode dot11Mode;
 	uint32_t nChannelBondingMode24GHz;
 	uint32_t nChannelBondingMode5GHz;